1. Field of the Invention
The present invention relates to a dishwasher using oscillatory flow generated from thermoacoustic effect that is configured such that thermoacoustic waves having high amplitude are generated from solar energy rather than electric energy, wherein the thermoacoustic waves make oscillating waves be directly transmitted to an air column and a water column formed in a closed end of a dishwashing pipeline. In this way, high-quality energy can be directly applied to washing water, whereby energy loss can be minimized, and the washing efficiency can be markedly increased.
2. Description of the Related Art
Generally, conventional thermoacoustic wave generators using solar light are configured such that a porous stack (solid block) is disposed in a transparent tube closed on one end thereof and thermoacoustic waves are generated by heating a portion thereof adjacent to the closed end of the transparent tube.
However, in conventional thermoacoustic wave generators, to generate high-frequency thermoacoustic waves, the size of the transparent tube must be reduced inversely proportional to the frequency of thermoacoustic waves, and a high thermal gradient between both ends of the porous stack must be maintained. Therefore, in practice it is very difficult to embody such conventional thermoacoustic wave generators. Referring to the result of research so far, it has been reported that the University of Utah, USA succeeded in producing a maximum acoustic wave of 3 kHz via this conventional technique.
In other words, it is no exaggeration to say that it is almost impossible to produce thermoacoustic waves in an ultrasonic wave range of 18 kHz or more using the above conventional technique.
Furthermore, research on generating thermoacoustic waves has focused on generating compression waves via a process of heating a very small micro-sized structure by momentarily applying Joule's heat resulting from electric energy to the structure and then cooling the structure. This process is repeated so that air surrounding the structure is expanded and cooled.
In an effort to overcome the problems of the conventional techniques pertaining to thermoacoustic wave generators, the applicant of the present invention proposed a thin metal plate membrane structure in Korean Patent Registration No. 10-1207380.
However, the technique of No. 10-1207380 is problematic in that the efficiency in producing high frequency is comparatively low because some solar light transmitted through a hole is lost in the air before it reaches the membrane structure. In addition, the size of a light interrupter must be greatly increased depending on the size of the thin metal plate. Thus, it is substantially difficult to commercialize the technique.
Therefore, there still is a problem in that it is difficult to substantially apply the conventional acoustic wave generator to various related industrial fields (for example, a dishwasher-related field, etc.)